Torsional torques of big turbine-generator shafts due to malsynchronization

In this work, a mathematical model for calculating and analyzing the torsional torques of large turbine-generator shafts that occur during various kinds of disturbances in the power network is described. On the basis of the mathematical model, a software package tested on an appropriate example is designed. Special attention is dedicated to torque analysis at malsynchronisation and at high-speed reclosure. It is shown that, in certain cases, the torsional torques of the shaft become several time larger than those rated, even for the torques occurring at three-pole short-circuits on generator busbars.